All sorts of services are available over the internet, including the ability to rent fairly expensive heat sensors. The advantage of renting over purchasing is that it saves on having to buy a specialty item that tends to be very pricey because of the lens involves as well as the limited quantity of manufacture. Cheaper infrared lenses are available, but they might not be up to scientific tasks. For infrared camera rental, check out this specialized webpage.
The customer is more likely to find infrared cameras for rent near where they live. There are specialty mail services for researchers who are willing to rent. Conditions such as providing a license number and making a security deposit might apply, but it is a temporary inconvenience for the ability to rent sensitive and valuable equipment. There is also the option to buy, but renting can be a fantastic money saver.